Abstract: The pressure solution differential stress at Taian Station was begun to be observed in 1991. In order to ensure the observed data to be normal and continuous, the interfernce factors of the instrument on the hole, the sensor leg and the downhole sensor have been eliminated, the hour data have been continuous for 4 years, the missing data are no more than 48 hours. By using many kinds of methods to identify anomalies, it is found that the data processed by the improved mutichannel Wienner filtering method showed obvious anomalies to the moderately strong earthquakes within the range of 400 km.